Early Signs of Rett Syndrome at 12–18 Months

Your daughter was reaching her milestones, and now something feels different — here's how to understand what you're noticing, gently and clearly.

In short

Rett Syndrome (ICD-11 LD90.0) often shows a distinctive pattern in the second year: a baby who was developing as expected begins to slow down or lose skills she had already gained — particularly purposeful hand use and emerging words. The hallmark sign is a loss of meaningful hand skills replaced by repetitive hand movements such as wringing, mouthing or hand-to-hand rubbing, alongside slowing head growth. These are signs to observe and discuss promptly with a clinician — never to diagnose at home.

Early signs to watch between 12 and 18 months

A pause or regression after early typical development

• Skills that were emerging — babbling, words, reaching, grasping — begin to fade or plateau
• A period of withdrawal or reduced eye contact and social interest, which can later partly recover

Loss of purposeful hand use

• Stops using hands to reach, hold or explore toys the way she used to
• Repetitive hand movements appear — wringing, squeezing, clapping, tapping, mouthing or washing-like motions, often near the midline

Movement and growth changes

• Slowing of head growth (the head circumference your paediatrician tracks may fall away from its earlier curve)
• Unsteady, wide-based or stiff walking, or delay in walking; reduced muscle tone or unusual stiffness

Communication and breathing

• Loss of emerging spoken words or reduced communicative sounds
• In some children, irregular breathing patterns while awake (breath-holding or fast breathing) — though these often become clearer a little later

What distinguishes this from ordinary variation is the loss or regression of skills a child once had, especially purposeful hand use, rather than a simple delay in gaining new ones.

When to seek a check

Because Rett Syndrome involves a genetic change and can affect movement, growth and breathing, any regression — losing skills your child previously had — warrants a prompt medical review with your paediatrician, who may arrange genetic testing (commonly MECP2) and onward specialist assessment. This is a medical-referral situation first; therapies such as occupational, physiotherapy and communication support then play a vital role in nurturing comfort, connection and ability.

The Pinnacle way

At Pinnacle Blooms Network, we walk beside families with warmth and a strengths-first lens — focusing on what your daughter can do and how we grow it. Targeted support like occupational therapy helps protect hand function, movement and daily participation, while you learn more about Rett Syndrome and what to expect. A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre under qualified clinician care; nothing here is a diagnosis. Across 70+ centres in 4 states and 4.95 lakh+ families served, our aim is steady, compassionate progress.

Trusted sources

Aligned with WHO ICD-11 (LD90.0 Rett syndrome), and developmental and child-health guidance from the American Academy of Pediatrics and HealthyChildren.org on monitoring milestones and acting early when skills are lost.

Next step — if you've noticed your daughter losing skills or changing how she uses her hands, please speak with your paediatrician now, and book a developmental screen with our clinical team on WhatsApp at +91 91001 81181 — let's understand this together.

This is general information, not a diagnosis — individual assessment and diagnosis require an appropriately qualified healthcare professional.